Hi Ben,
You could also read the register CNTFRQ_EL0 [https://developer.arm.com/docs/ddi0595/b/aarch64-system-registers/cntfrq_el0] to double check the value.
As to the max IRQ, you can read it from the GICD_TYPER [https://developer.arm.com/docs/ihi0048/b/arm-generic-interrupt-controller-ar...]. The ITLinesNumber field indicates the maximum number of interrupts supported by the GIC.
Hope that will help.
Regards,
Yanyan
From: "Turner, Ben"
Date: Thursday, 20 February 2020 at 3:06 am
To: "Shen, Yanyan (Data61, Kensington NSW)" , "devel@sel4.systems"
Cc: "Millar, Curtis (Data61, Kensington NSW)" , "Mcleod, Kent (Data61, Kensington NSW)"
Subject: RE: [seL4] Adding Platform Support: CAmkES-ARM-VM: VM_Minimal: Raspberry Pi 3b
Hi Shen,
Thanks for the advice. I may have found the TIMER_FREQUENCY (although I’m not certain) – the boot log has an entry:
arch_timer: cp15 timer(s) running at 54.00MHz
This is the only possibly relevant timer reference I can find?
I haven’t had any luck with the MAX_IRQ value though. The only value in the boot log that could relate is:
NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
But 16 seems way lower than I would expect… The value for the RPi3, for example, is 127!
Thanks,
Ben Turner
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